WASHINGTON (USA TODAY) -- John Brennan's nomination to lead the CIA was delayed Wednesday by a filibuster led by Sen. Rand Paul, R-Ky., about concerns about the legality of drone strikes against U.S. citizens.    

"I'm going to speak as long as I can to draw attention to something I find very disturbing," said Paul, who started speaking at 11:45 a.m.

WATCH: Rand Paul's filibuster live

What started in the morning as a solo effort turned into a eight-senator debate that included one Democrat, Ron Wyden of Oregon, and seven Republicans questioning the constitutionality of drone strikes on U.S. citizens at home and abroad.

MORE: 5 longest filibusters in Senate history

"No American should be killed by a drone on American soil without first being charged with a crime, without first being found guilty of a crime by a court," Paul said. "How can you kill someone without going to a judge, or a jury?"

The federal government has not conducted such operations and doesn't plan to, Attorney General Eric Holder told Paul in a March 4 letter. But, Holder added, it was possible President Obama could be forced by an "extraordinary circumstance" to kill citizens inside the United States, and he cited the Pearl Harbor and 9/11 attacks as examples.

During his filibuster, Paul said the fuzziness of such language created a slippery slope that could lead to the targeting of citizens who merely have different opinions about policies than the president.

"You can't be judge, jury and executioner all in one," Paul said.

Senate Majority Leader Harry Reid, D-Nev., took the floor around 4:30 to say any vote to end debate on Brennan's nomination or to approve him as CIA director would happen Thursday.

Paul said during his filibuster that his opposition was not about Brennan himself, but the constitutional issues involved. "We really just want [Obama] to say he won't" attack noncombatants on U.S. soil.

Democrats who lead the Senate could move Brennan's nomination to a vote, Paul said, if they would introduce a resolution saying they would not advocate the killing of noncombatants with drone strikes.

Wyden, a longtime critic of excessive government intelligence and surveillance programs, said "the senator from Kentucky has made a number of important points."

There are times, Wyden said, when a U.S. citizen who takes up arms against the United States while overseas can be attacked by a drone. But the executive branch of government, he said, should not be allowed to "conduct such a far-reaching policy without scrutiny."

It's not a partisan issue, Paul said, noting that he voted to support the nominations of John Kerry and Chuck Hagel, the secretaries of State and Defense.

Paul and other senators had delayed a full Senate vote on Brennan's nomination until they received more information about the drone program. The White House provided Justice Department documents on the drone program to the Senate Intelligence Committee on Tuesday.

The committee then voted 12-3 to approve Brennan's nomination.

Brennan, the White House's top counterterrorism adviser, was closely linked to the drone program. The administration has used the unmanned aircraft to regularly target suspected terrorists in the Middle East and Africa.

In 2011, U.S.-born cleric Anwar al-Awlaki was killed by a drone strike in Yemen, raising questions about the use of the armed drones on American citizens.

Republican Sens. John McCain of Arizona and Lindsey Graham of South Carolina had used Brennan's nomination to air concerns about the administration's handling of the Sept. 11, 2012, attack on the U.S. Consultate in Benghazi, Libya, that killed four Americans, including the U.S. ambassador.

McCain and Graham said they would oppose Brennan unless they got classified documents detailing the administration's actions immediately following the attack, the Associated Press reported.

The White House has said it provided more documents to lawmakers about that attack.

Before coming to the White House, Brennan served 25 years in the CIA.